Agents of Cutaneous Mycoses

Question 1

Enumerate the 3 causative agents of dermatophytosis.

Answer 1

1) Trichophyton
2) Microsporum
3) Epidermophyton

Question 2

General term for causative agents of dermatophytosis.

Answer 2

dermatophytes

Question 3

General term for diseases associated with dermatophytes.

Answer 3

dermatophytosis

Question 4

– a fungal disease of the keratinized tissue of humans
– keratinophilic

Answer 4

dermatomycoses

Question 5

What are the 2 sizes of reproductive cells produced by dermatophytes?

Answer 5

microconidia and macroconidia

Question 6

What type of reproduction is seen in dermatophytes?

Answer 6

heterothallic

Question 7

What type of reproduction whereby it requires the combination of two distinct mating types?

Answer 7

heterothallic

Question 8

Identify the type of dermatophyte based on habitat:

• produce large numbers of conidia
• most readily identified species

Answer 8

geophilic

Question 9

Identify the type of dermatophyte based on habitat:

• soil

Answer 9

geophilic

Question 10

Identify the type of dermatophyte based on habitat:

• typically adapted to live on animals
• Fewer conidia are produced

Answer 10

zoophilic

Question 11

Identify the type of dermatophyte based on habitat:

• adapted exclusively to human hosts
• almost always encountered as agents of human disease
• infections are seldom inflammatory

Answer 11

anthropophilic

Question 12

Identify the causative agent.

Tinea favosa

Answer 12

Trichophyton schoenleinii

Question 13

Identify dermatophytosis:

✓ crusty lesions
✓ scutula (crusty, cup-shaped flakes) are formed
✓ hair loss, scar tissue formation

Answer 13

Tinea favosa

Question 14

Identify dermatophytosis:

• infection of the nails
• subungual
• thick
• discolored
• flaky

Answer 14

Onychomycosis

Question 15

Identify dermatophytosis:

• athlete’s foot
• contact with infected skin scales
• can be genetic

Answer 15

Tinea pedis

Question 16

Identify dermatophytosis:

• extensive scaling
• fissuring
• erythema

Answer 16

Tinea pedis

Question 17

What is the other name for athlete’s foot disease?

Answer 17

Moccasin foot

Question 18

Identify the dermatophyte.

▪ Favic Chandelier
▪ Moose Antler Hyphae

Answer 18

Trichophyton schoenleinii

Question 19

Describe the colony morphology of Trichophyton schoenleinii.

Answer 19

suede-like and deeply folded

Question 20

What form of tinea capitis is common among children and colonizes the outer portion of the hair shaft (ectothrix)?

Answer 20

Gray patch ringworm

Question 21

What form of tinea capitis colonizes the inside (endothrix) of the hair shaft whereby weak, brittle, infected hair shafts break off at the scalp, leaving the black dot stubs?

Answer 21

Black dot ringworm

Question 22

Identify the dermatophyte.

• anthropophilic
• Microconidia: chlamydospores
• Macroconidia: odd shaped and has chlamydoconidia-like swellings

Answer 22

Microsporum audouinii

Question 23

Identify the dermatophyte.

• Microconidia: tear-shaped or balloon-shaped
• Macroconidia: cylindrical

Answer 23

Trichophyton tonsurans

Question 24

What treatments may be given to patients with onychomycosis?

Answer 24

terbinafine and itraconazole

Question 25

Identify the dermatophyte. - produces only 1 size of conidia

Answer 25

Epidermophyton floccosum

Question 26

Identify the dermatophyte. - yellow to yellow-tan - flat with feathered edges - small in diameter

Answer 26

Epidermophyton floccosum

Question 27

Identify the dermatophyte. - zoophilic - spindle-shaped macroconidia (3-15 cells)

Answer 27

Microsporum canis

Question 28

Identify the dermatophyte. - fluffy and white colonies - reverse side: lemon-yellow pigment, especially on potato dextrose agar

Answer 28

Microsporum canis

Question 29

Identify the dermatophyte. - geophilic - macroconidia: cigar-shaped, rounded ends (6 cells)

Answer 29

Microsporum gypseum

Question 30

Identify the dermatophyte. - tan to buff conidial masses are typical of fresh isolates - abundant brown to red pigment can form beneath some strains, but others remain colorless.

Answer 30

Microsporum gypseum

Question 31

Identify the dermatophyte. - slow-growing anthropomorphic dermatophyte - cottony white colonies

Answer 31

Microsporum audouinii

Question 32

Identify the dermatophyte. - globose and grape-like microconidia

Answer 32

Trichophyton mentagrophytes

Question 33

Identify the dermatophyte. - pencil-shaped macroconidia (3-8 cells)

Answer 33

Trichophyton rubrum

Question 34

What is the culture media used for Trichophyton tonsurans?

Answer 34

Sabouraud dextrose agar

Question 35

What is the leading cause of tinea capitis in children?

Answer 35

Trichophyton tonsurans